Process Study On The Formation Of Multilayer Diamond Abrasive And Ni-Cr Alloy By Laser Brazing

As an advanced grinding wheel preparation process,laser brazing can be used to prepare diamond grinding wheel which can ensure the high metallurgical bonding strength of abrasive and binder due to its advantages of high maneuverability,high energy density and small heating area.However,about the existing laser brazing in grinding wheel manufacturing,the application of the research is mainly aimed at single diamond abrasive grinding wheel and solder during the soldering process,bonding mechanism between diamond and matrix,and the preparation of the monolayer diamond grinding wheel after wear,abrasion,crushing,no diamond grits,shorter working life,low use efficiency.With the development of laser sintering forming technology and additive manufacturing technology,it has become a feasible new technology to realize the forming and manufacturing of multilayer diamond grinding wheel by using laser brazing technology.In this paper,laser brazing technology was used to braze Ni-Cr alloy filler and diamond abrasive on 45 steel substrate.By establishing the evaluation index of brazing forming characteristics at each stage,the characteristic parameters of brazing layer forming were extracted.Combined with the analysis of the micro-forming process of the brazing layer,the micro-forming mechanism and law of the multilayer abrasive brazing layer were studied.The wear experiments of multilayer abrasive particles were carried out and a systematic evaluation was made on the laser brazing of multilayer diamond layer by layer.Specific research work includes the following aspects:(1)Based on the summary of previous literature and books on the forming quality of diamond grinding wheel,the forming quality of laser additive manufacturing and the influencing factors,the shape parameter indexes and evaluation methods of brazing layer forming were successively established frome single channel brazing,single layer brazing to multi-layer brazing.(2)Respectively,the single way of orthogonal and single factor experiment,single multichannel brazing experiments and multi-layer laser brazing diamond grits experiment were carried out.Combined with laser brazing diamond grits forming step by step a characteristic parameter and surface morphology,the alloy powder fusion degree and spreading ability on diamond parcels,brazing layer and substrate bonding strength,and the quality of the brazing layer forming has carried on the comprehensive system of evaluation.The influence of brazing process parameters on forming to was studied.(3)Through the observation and analysis of the microstructure of brazing layer structure,composition,and microstructure of diamond,in single channel,single and multi-layer laser soldering,thr brazing layer structure growth rule,micro elements distribution,diamond grits and solder combination principle and abrasive damage were discussed.(4)The wear experiments of single-layer laser brazing test blocks,multi-layer laser brazing test blocks,bronze test blocks,and resin bond test blocks were carried out.The multi-layer laser brazing test blocks were systematically evaluated by combining the wear curve and the wear pattern of diamond.